/Engine/Plugins/Runtime/DataRegistry/Source/DataRegistry/Public/DataRegistry.h
Fills in a map with all cached (and precached) ids and items for fast iteration. This will use the current resolve context so may not always be valid, and multiple ids can map to the same raw pointer
virtual [FDataRegistryCacheGetResult](API\Plugins\DataRegistry\FDataRegistryCacheGetResult) GetAllCachedItems ( [TMap](API\Runtime\Core\Containers\TMap)< [FDataRegistryId](API\Plugins\DataRegistry\FDataRegistryId), const uint8 * > & OutItemMap, const [UScriptStruct](API\Runtime\CoreUObject\UObject\UScriptStruct) *& OutItemStruct ) const